Coated cutting tool and method

Abstract

A coated cutting tool includes a substrate and a coating, wherein the coating has a PVD layer being a compound of the formula Ti1-xSixCaNbOc, wherein 0.10<x≤0.30, 0≤a≤0.75, 0.25≤b≤1, 0≤c≤0.2, and a+b+c=1. The PVD layer is a NaCl structure solid solution. The disclosure further relates to a method for producing the PVD layer by cathodic arc evaporation using a pulsed bias voltage of from about −40 to about −450 V to the substrate and using a duty cycle of less than about 12% and a pulsed bias frequency of less than about 10 kHz.

The invention claimed is: 
     
       1. A coated cutting tool comprising a substrate and a coating, wherein the coating includes a PVD layer being a compound of the formula Ti 1-x Si x C a N b O c , wherein 0.10<x≤0.30, 0≤a≤0.75, 0.25≤b≤1, 0≤c≤0.2, and a+b+c=1, wherein the PVD layer is a NaCl structure solid solution and wherein the PVD layer has a FWHM (Full Width at Half Maximum) value for the cubic ( 111 ) peak in X-ray diffraction being ≤0.35 degrees (2theta). 
     
     
       2. The coated cutting tool according to  claim 1 , wherein in the formula Ti 1-x Si x C a N b O c , 0.12≤x≤0.25. 
     
     
       3. The coated cutting tool according to  claim 1 , wherein the FWHM value for the cubic ( 111 ) peak in X-ray diffraction is ≤0.25 degrees (2theta). 
     
     
       4. The coated cutting tool according to  claim 1 , wherein the PVD layer has a residual stress being >−3 GPa. 
     
     
       5. The coated cutting tool according to  claim 1 , wherein the PVD layer includes faceted crystal grains on its surface. 
     
     
       6. The coated cutting tool according to  claim 1 , wherein a thickness of the PVD layer is from about 0.5 to about 20 μm. 
     
     
       7. The coated cutting tool according to  claim 1 , wherein the PVD layer is an arc evaporation deposited layer. 
     
     
       8. A method for producing a coating on a substrate, the coating including a PVD layer deposited by cathodic arc evaporation, the PVD layer being a compound of the formula Ti 1-x Si x C a N b O c , wherein 0.10<x≤0.30, 0≤a≤0.75, 0.25≤b≤1, 0≤c≤0.2, and a+b+c=1, and wherein the PVD layer is a NaCl structure solid solution and wherein the PVD layer has a FWHM (Full Width at Half Maximum) value for the cubic ( 111 ) peak in X-ray diffraction being ≤0.35 degrees (2theta), the PVD layer being deposited by applying a pulsed bias voltage of from about −40 to about −450 V to the substrate and using a duty cycle of less than about 12% and a pulsed bias frequency of less than about 10 kHz. 
     
     
       9. The method according to  claim 8 , wherein the duty cycle is from about 2 to about 10%. 
     
     
       10. The method according to  claim 8 , wherein the pulsed bias frequency is from about 0.1 to about 8 kHz. 
     
     
       11. The method according to  claim 8 , wherein the pulsed bias voltage is from about −50 to about −350 V.